It is widely recognised that public-sector purchasers tend to discriminate in favour of domestic suppliers. We study the consequences of home-biased public procurement on international specialisation. In the theoretical analysis we find two effects. First, a country will specialise in the sector for which it has relatively large home-biased procurement (the "pull" effect). Second, home-biased procurement can counter agglomeration forces and thereby attenuate the overall degree of international specialisation (the "spread" effect). Our empirical analysis, conducted on input-output data for the European Union, yields supporting evidence for the pull effect and some support for the spread effect.